Publication Date:
2013-10-02
Description:
Nature Physics 9, 626 (2013). doi:10.1038/nphys2702 Authors: Sumilan Banerjee, Onur Erten & Mohit Randeria The electronic properties of the polar interface between insulating oxides is a subject of great interest. An exciting development is the observation of robust magnetism at the interface of two non-magnetic materials, LaAlO3 (LAO) and SrTiO3 (STO). Here we present a microscopic theory for the formation and interaction of local moments that depends on essential features of the LAO/STO interface. We show that correlation-induced moments arise owing to interfacial splitting of orbital degeneracy. We find that conduction electrons with a gate-tunable Rashba spin–orbit coupling mediate ferromagnetic exchange with a twist. We predict that the zero-field ground state is a long-wavelength spiral. Its evolution in an external field accounts semi-quantitatively for torque magnetometry data and describes qualitative aspects of the scanning superconducting quantum interference device measurements. We make several testable predictions for future experiments.
Print ISSN:
1745-2473
Electronic ISSN:
1745-2481
Topics:
Physics
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